Metal ceramic substrate and method for producing the same

Abstract

A metal ceramic substrate and a method for producing the same are provided. The metal ceramic substrate includes a ceramic substrate layer, a metal solder layer, and a conductive metal layer. The metal solder layer includes a first sub-solder layer and a second sub-solder layer. The first sub-solder layer is disposed on a side surface of the ceramic substrate layer. A composition of the first sub-solder layer includes a first metal solder material, and the first metal solder material includes a metal copper and an active metal, and does not include a metal silver. The second sub-solder layer is disposed on a side surface of the first sub-solder layer. A composition of the second sub-solder layer includes a second metal solder material. The second metal solder material includes a metal tin and a metal copper, and does not include a metal silver.

What is claimed is: 
     
         1 . A metal ceramic substrate, comprising:
 a ceramic substrate layer;   a metal solder layer including:
 a first sub-solder layer disposed on a side surface of the ceramic substrate layer, wherein a composition of the first sub-solder layer includes a first metal solder material, and the first metal solder material includes a metal copper (Cu) and an active metal, and does not include a metal silver (Ag), and wherein a thickness of the first sub-solder layer is greater than 6 micrometers; and 
 a second sub-solder layer disposed on a side surface of the first sub-solder layer that is away from the ceramic substrate layer, wherein a composition of the second sub-solder layer includes a second metal solder material, and the second metal solder material includes a metal tin (Sn) and a metal copper (Cu), and does not include a metal silver (Ag), and wherein a thickness of the second sub-solder layer is greater than 6 micrometers; and 
   a conductive metal layer disposed on a side surface of the second sub-solder layer that is away from the first sub-solder layer.   
     
     
         2 . The metal ceramic substrate according to  claim 1 , wherein, based on a total weight of the first metal solder material being 100 weight percent, a ratio between a content of the metal copper (Cu) and a content of the active metal ranges from 80%:20% to 50%:50%; wherein, based on a total weight of the second metal solder material being 100 weight percent, a ratio between a content of the metal tin (Sn) and a content of the metal copper (Cu) ranges from 80%:20% to 30%:70%. 
     
     
         3 . The metal ceramic substrate according to  claim 1 , wherein, based on a total weight of the first metal solder material being 100 weight percent, a ratio between a content of the metal copper (Cu) and a content of the active metal ranges from 65%:35% to 55%:45%; wherein, based on a total weight of the second metal solder material being 100 weight percent, a ratio between a content of the metal tin (Sn) and a content of the metal copper (Cu) ranges from 80%:20% to 65%:35%; wherein the entire metal solder layer does not contain the metal silver (Ag). 
     
     
         4 . The metal ceramic substrate according to  claim 1 , wherein a content of the metal copper (Cu) of the first sub-solder layer is greater than a content of the metal copper (Cu) of the second sub-solder layer. 
     
     
         5 . The metal ceramic substrate according to  claim 1 , wherein the thickness of the first sub-solder layer is between 10 micrometers and 18 micrometers, and the thickness of the second sub-solder layer is between 10 micrometers and 18 micrometers. 
     
     
         6 . The metal ceramic substrate according to  claim 1 , wherein the active metal is selected from the group consisting of titanium (Ti), zirconium (Zr), tantalum (Ta), niobium (Nb), vanadium (V), hafnium (Hf), titanium hydride (TiH 2 ), zirconium hydride (ZrH 2 ), tantalum hydride (TaH 2 ), niobium hydride (NbH), vanadium hydride (VH 2 ), and hafnium hydride (H 2 Hf 2 ); wherein the ceramic substrate layer is selected from the group consisting of a silicon nitride ceramic substrate, a silicon carbide ceramic substrate, an aluminum nitride ceramic substrate, and an alumina ceramic substrate; wherein the conductive metal layer is selected from the group consisting of a metal copper foil, a metal aluminum foil, and a copper-aluminum alloy foil. 
     
     
         7 . A method for producing a metal ceramic substrate, comprising:
 coating a first solder paste onto a side surface of a ceramic substrate layer, and drying the first solder paste at a high temperature to form a first sub-solder layer; wherein the first solder paste includes a first metal solder material and a first organic medium, and the first metal solder material includes a metal copper (Cu) and an active metal, and does not include a metal silver (Ag); wherein a thickness of the first sub-solder layer is greater than 6 micrometers;   coating a second solder paste onto a side surface of the first sub-solder layer that is away from the ceramic substrate layer, and drying the second solder paste at a high temperature to form a second sub-solder layer; wherein the second solder paste includes a second metal solder material and a second organic medium, and the second metal solder material includes a metal tin (Sn) and a metal copper (Cu), and does not include a metal silver (Ag); wherein a thickness of the second sub-solder layer is greater than 6 micrometers; and   disposing a conductive metal layer onto a side surface of the second sub-solder layer that is away from the first sub-solder layer.   
     
     
         8 . The method according to  claim 7 , wherein, in the first sub-solder layer, a weight percentage concentration of the first metal solder material is not less than 70 wt %; wherein, in the second sub-solder layer, a weight percentage concentration of the second metal solder material is not less than 70 wt %. 
     
     
         9 . The method according to  claim 8 , wherein, based on a total weight of the first metal solder material being 100 weight percent, a ratio between a content of metal copper (Cu) and a content of the active metal ranges from 80%:20% to 50%:50%; wherein, based on a total weight of the second metal solder material being 100 weight percent, a ratio between a content of the metal tin (Sn) and a content of the metal copper (Cu) ranges from 80%:20% to 30%:70%. 
     
     
         10 . The method according to  claim 8 , further comprising: performing a high-temperature vacuum sintering process to tightly connect the conductive metal layer to the ceramic substrate layer through a metal solder layer formed by the first sub-solder layer and the second sub-solder layer; wherein an operation temperature of the high-temperature vacuum sintering process is between 600° C. and 900° C.